The present invention relates to play and/or exercise hoops of the type commonly known as HULA HOOPS.
Play hoops of the HULA HOOP type are widely known. They are used for rolling and gyrating about the hips and other parts of the body. Hoops are typically made from a length of plastic tubing by bending the length into a circle and joining the ends.
Such hoops do not have any internal damping, which restricts their efficiency. To gyrate a conventional hoop about the hips requires considerable work because the needed rotational speed is quite high.
Another drawback of previous hoops is that they are too light. The conventional hoops can be made of heavier-walled plastic tubing, but this is expensive and makes for difficult bending into the required circular form.
One previous hoop designed by the present applicant had water contained therein in an attempt to solve these problems, but this earlier liquid-filled hoop was not successful. The water leaked out and the hoop did not function properly.
A play and/or exercise hoop is disclosed in copending application Ser. No. 09/395,359, the contents of which are incorporated herein by reference. Such play and exercise hoop, which has achieved commercial success, is provided with internal inertia shifting. This is accomplished by partially filling the hollow tubular hoop with water. The trapped water increases the mass, provides internal damping of any motion (especially axial acceleration or deceleration), and leads to novel motions because of the shifting of the water inside.
Unlike the previous water-containing hoop, the circular hoop of the copending application allows the trapped water or liquid to freely circulate all the way around the hoop circumferentially; thus when the hoop is rotated about the body, the liquid remains in the part of the hoop opposite the part in contact with the body of the user, and the rolling motion of the hoop is smooth. The flow of the water around the circumference of the hoop must not be blocked if desirable toy dynamics are to be achieved.
The water filling of the copending application makes the typical HULA-HOOP hip gyration in which the hoop remains elevated, and similar gyrations, easier. This is because the water decreases the rotational speed needed in the hip motion, and slower rotation about the body is possible. Centrifugal force causes the water to shift as the circular hoop is rotated or gyrated about the hips, permitting a slower, easier and less tiring rotation.
The water-tight hoop-joint of the copending application includes a coupling tube, disposed inside the outer main hoop tube at the joint, having a large bore through which the liquid can freely flow. The coupling tube is adapted to receive a seal, such as an 0-ring, between the outer wall of the inner coupling and inner wall of the outer hoop tube. This construction, however, is undesirably costly and inefficient as regards the manufacturing process.
The present invention relates to an improvement over the hoop of the copending application, particularly as regards the joint between the two ends of the hoop tube. Thus, according to the present invention, an improved and less expensive joint is provided by the use of a mechanical fastening and a shrink tube, without inhibiting the flow of liquid past the joint and without leaking of water from the hoop joint.